Asking all the right questions

"I've always been struck by how philosophically minded children are," says Stephen Law. "They ask questions and they get an answer, and behind that answer they find another question to ask, and it doesn't take long before they're starting to question some of our most basic and fundamental beliefs. If you repeatedly ask 'Why?', it's not long before you're really hitting philosophical bedrock."

The thought of dealing with philosophical bedrock at bedtime might be many parents' idea of hell; but philosophy lecturer Law believes in getting them while they're young. His first book, The Philosophy Files, goes straight to the heart of some of the most vexed questions there are to ask: What's real? Where do right and wrong come from? How do I know the world isn't virtual? Should I eat meat? And not forgetting: Does God exist?

Accessible, entertaining, and plentifully illustrated by Daniel Postgate, the only question it doesn't tackle head on is why nobody's written a book like it before. Unlike Jostein Gaarder's Sophie's World or Alain de Botton's The Consolations of Philosophy, this is no dinner-party roll call of the great and the dead. It's philosophy in action rather than philosophy in aspic.

What Law shares with Gaarder and de Botton, though, is the irresistable impulse to popularise. "Which is considered to be career suicide," he says. "At least that's what I've been told. But then I'm not particularly ambitious in the sense of working my way up the academic ladder. I mean, the average philosophical journal article is read by a total of eight people. And while I do write journal articles, I don't think that's going to change the world, really. Whereas a book can, in some subtle but important way, change people's lives. And I do passionately believe that it's important that people think about these big questions in the course of their everyday lives. Moral questions, especially. It's slightly depressing, I think, if you live in a society where people don't."

He's been interested in the big questions for as long as he can remember, he says; but it took him a while to figure out that repeatedly asking "Why?" might actually amount to a legitimate occupation. Academia wasn't alien to him - he grew up in Cambridge, and his father had a doctorate in sociology - but he messed up at school, thought he'd blown any chance of further study, and had no idea that philosophy existed as a subject in its own right.

The first time he embarked on A-levels, he says, he was asked to leave - "basically because I was lazy and good for nothing. I don't blame them at all". A year or so later he tried another subject combination at another college, but found himself too irritated by the exam-oriented mentality of the syllabus to see it through. "You weren't allowed to do anything other than regurgitate," he says, "when what I really wanted to do was ask the questions."

So, after a couple of brief spells as a sand-blaster and damp-proofer, he settled into four years as a postman in Girton, just outside Cambridge. He was the only one on the job who never got a Christmas tip. "I wasn't a very accurate postman," he concedes now. "In fact I was a very bad postman. Possibly the worst postman Girton ever had."

But those four years gave him a lot of time to think, and to read. Left to his own devices, he consumed books. "One book would lead me to another, and then another, until eventually I ended up reading nothing but philosophy books. And I suddenly realised that that's what I'd always wanted to do - but that I'd never known what it was called."

He was 23: just old enough to qualify as a mature student, which meant that he didn't need A-levels after all. So he ditched the post office, bummed around India for a few months, and - "like a miracle" - was accepted to read philosophy at London's City University. Some of the papers he'd written for himself in the course of his reading helped persuade them that he was serious about doing a degree. Very serious, in fact. He got a gratifying first, went on to secure the coveted BPhil at Trinity College, Oxford, and then netted himself a prestigious junior research fellowship at Queen's, before taking up a teaching post at London University's Heythrop College four years ago.

It's precisely the maverick combination of passion, rigour, patience and sedition that makes Law such an engaging writer and teacher. But it's only now, reaping handsome praise for The Philosophy Files, that he's finally given up worrying that he might not be clever enough, posh enough or cynical enough to be a proper academic. "I did go through a major crisis of confidence at Oxford," he says. "I felt that I didn't fit into that mould particularly, and for a while I just couldn't produce any papers at all. But the fact is, I'm doing what I'm doing now because I enjoy it. It's good fun. I don't care any more what people think about me."

Now 39, he's delighted that the book he has been conjuring in his head for so many years - a real philosophy book for kids, which students and adults could enjoy too - finally exists. A kind of career suicide note with knobs on, complete with cartoons and dayglo cover.

"I wanted it to be an adventure in thinking of the sort I wish someone had written for me when I was younger," he says. "I would never have appreciated someone giving me a textbook which explained what Descartes had to say about this or what Plato said about that. But if someone had actually engaged me in my own language and on my own terms, talking about questions in the way that I wanted to talk about them at that age, then I would have lapped it up."